Q85 / 200 · NEET 2009 (Screening) · Chemistry
Which one of the elements with the following outer orbital configurations may exhibit the largest number of oxidation states ?
- A$3 d^3, 4 \mathrm{~s}^2$
- B$3 d^5, 4 \mathrm{~s}^1$
- Correct answerC$3 d^5, 4 s^2$
- D$3 d^2, 4 s^2$
Solution
Key Idea Number of oxidation states exhibited by d-block elements is the sum of number of electrons (unpaired) in d-orbitals and number of electrons in s-orbital.
(a) $3 \mathrm{~d}^3, 4 \mathrm{~s}^2 \Rightarrow \mathrm{O} . \mathrm{S}=3+2=5$
(b) $3 \mathrm{~d}^5, 4 \mathrm{~s}^1 \Rightarrow \mathrm{O} . \mathrm{S}=5+1=6$
(c) $3 \mathrm{~d}^5, 4 \mathrm{~s}^2 \Rightarrow \mathrm{O} . \mathrm{S}=5+2=7$
(d) $3 \mathrm{~d}^2, 4 \mathrm{~s}^2 \Rightarrow \mathrm{O} . \mathrm{S}=2+2=4$
Hence, element with $3 \mathrm{~d}^5, 4 \mathrm{~s}^2$ configuration exhibits largest number of oxidation states.
Hence, the correct answer is option: 'C'.